What do you know about Green Technology?

Green technology covers a wide range of innovations that can increase the efficiency of our energy production and use, while minimizing our impact on the planet. Test your knowledge of seven engineering feats and roadblocks that are affecting our environment.

1

Which of the following are downsides associated with producing solar panels?

The quartz is extracted from mines, putting miners at risk of the lung disease silicosis

Turning silicon into purer polysilicon creates the highly-toxic compound silicon tetrachloride, which acidifies soil and emits fumes when dumped near water

Hydrofluoric acid is used to clean the silicon wafers, and while it works well, if spilled it destroys tissue and decalcifies animals’ bones

All of the above

Nice Try!

“Many people today view photovoltaics as a panacea for our energy woes, given how dirty most of the alternatives are. But that does not mean we should turn a blind eye to the darker side of this technology. Indeed, we need to consider it very carefully. And just maybe, with a sustained effort by consumers, manufacturers, and researchers, the photovoltaics industry will one day be truly, not just symbolically, green.”

“Many people today view photovoltaics as a panacea for our energy woes, given how dirty most of the alternatives are. But that does not mean we should turn a blind eye to the darker side of this technology. Indeed, we need to consider it very carefully. And just maybe, with a sustained effort by consumers, manufacturers, and researchers, the photovoltaics industry will one day be truly, not just symbolically, green.”

Drag created by the turbines limits the amount of kinetic energy that land-based wind farms can extract to about 1.5 MW/km2. How much energy can wind farms in the open ocean extract per square kilometer?

1.0 MW/km2

1.5 MW/km2

3.0 MW/km2

6.0 MW/km2

Nice Try!

“The atmosphere is more generous out in the open ocean. There […] wind farms could be packed more tightly, because energy should flow down from above the boundary layer to quickly restore winds depleted by wind turbine rotors. In some regions, such as the North Atlantic, the simulations suggest that large wind farms can extract 6 MW/km2 or more.”

“The atmosphere is more generous out in the open ocean. There […] wind farms could be packed more tightly, because energy should flow down from above the boundary layer to quickly restore winds depleted by wind turbine rotors. In some regions, such as the North Atlantic, the simulations suggest that large wind farms can extract 6 MW/km2 or more.”

Hydrogen fuel cell cars are eco-friendly, but adoption has been slow because they can suffer irreversible damage when exposed to temperatures below 0°C. Which of the following engineering areas still needs improvement for them to be useful in cold weather countries?

Managing water during shutdown and startup

Temperature uniformity in the stack during heating

Heat utilization, cooling, and humidification

All of the above

Nice Try!

“More automotive industrial strategies, including real time methods, need to be developed to predict parking time and energy requirement, reduce energy wastage and increase reliability during subfreezing temperatures. Improved techniques to manage water during shutdown and startup; improved temperature uniformity in the stack during heating; and improved heat utilization, cooling, and humidification techniques are needed. It is important also to improve membrane/cell stability under freeze/thaw cycles and membrane conductivity under low humidity conditions.”

“More automotive industrial strategies, including real time methods, need to be developed to predict parking time and energy requirement, reduce energy wastage and increase reliability during subfreezing temperatures. Improved techniques to manage water during shutdown and startup; improved temperature uniformity in the stack during heating; and improved heat utilization, cooling, and humidification techniques are needed. It is important also to improve membrane/cell stability under freeze/thaw cycles and membrane conductivity under low humidity conditions.”

How much has the price of energy storage via large-scale batteries decreased since 2010?

20%

40%

80%

160%

Nice Try!

“And just as the price of solar energy has dropped over the past decade—for example, a mid-November auction in Mexico for new generating capacity resulted in prices that approached $20/MWh—so, too, has the price of storage. It has fallen by as much as 80 percent since 2010.”

“And just as the price of solar energy has dropped over the past decade—for example, a mid-November auction in Mexico for new generating capacity resulted in prices that approached $20/MWh—so, too, has the price of storage. It has fallen by as much as 80 percent since 2010.”

Data centers are notorious for their intensive energy use. What’s the most efficient way to keep one cool?

Mechanical cooling (air conditioning)

Ocean water (building it on the seafloor)

Free-air cooling (outdoor air)

Snow cooling (snowmaking machines)

Nice Try!

“Of course, the colder the surrounding ocean, the better this scheme will work. To get access to chilly seawater even during the summer or in the tropics, you need only put the pods sufficiently deep. For example, at 200 meters’ depth off the east coast of Florida, the water remains below 15 °C all year round.”

“Of course, the colder the surrounding ocean, the better this scheme will work. To get access to chilly seawater even during the summer or in the tropics, you need only put the pods sufficiently deep. For example, at 200 meters’ depth off the east coast of Florida, the water remains below 15 °C all year round.”

True or false: the permanent-magnet synchronous machine (PMSM) motors used in the vast majority of electric cars are the best-performing electric motors to date.

True

False

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By combining the technology of PMSM motors with salient-pole synchronous machine (SPSM) motors, the resulting motor “is able to produce almost 6 percent more torque and attain 2 percent higher peak efficiency. And in the driving cycle the improvement is even better: It requires 4.4 percent less energy. That means a car that would have gone 100 kilometers on a charge can, with this motor, go 104.4 km.”

By combining the technology of PMSM motors with salient-pole synchronous machine (SPSM) motors, the resulting motor “is able to produce almost 6 percent more torque and attain 2 percent higher peak efficiency. And in the driving cycle the improvement is even better: It requires 4.4 percent less energy. That means a car that would have gone 100 kilometers on a charge can, with this motor, go 104.4 km.”

Pumping water uphill to store energy in hydropower reservoirs is far from a new idea. But with the rise of intermittent solar and wind power, this technology could see a revival. Which country has the most pumped storage plants, capable of absorbing and discharging 26 GW of power?

Japan

China

United States

Austria

Nice Try!

“In post-Fukushima Japan, these nimble storage plants have a new opportunity to shine: managing the more than 10 GW of solar and other renewable energy capacity that has been installed in Japan since the March 2011 meltdowns and the subsequent idling of the country’s nuclear reactors.”

“In post-Fukushima Japan, these nimble storage plants have a new opportunity to shine: managing the more than 10 GW of solar and other renewable energy capacity that has been installed in Japan since the March 2011 meltdowns and the subsequent idling of the country’s nuclear reactors.”

Don’t worry, green technologies are called “emerging” for a reason. You’ll get more exposure as they grow. Want to speed up the learning process? Visit https://spectrum.ieee.org/green-tech for some great introductory reading.